AN/UQN-4A Sonar Sounding Set

The Sonar Sounding Set AN/UQN-4A is a water depth measuring system that provides the distance between the ship keel and the ocean bottom. The AN/UQN-4A transmits acoustic pressure pulses into the ocean which reflect off the bottom and return to ownship. The return energy is converted into electrical energy for presentation as a measurement of water depth. Water depth is continually presented on the Depth Indicator's digital numeric display and may be permanently recorded on the Receiver Transmitter's chart recorder. The AN/UQN-4A measures water depth from 4 feet to 6,000 fathoms, and incorporates pulse-width discriminator and a range gate to eliminate false echo responses.